*2.3. PLES classification*

PLES data in Ningbo of 2010 and 2018 evolved from land use data (1 × 1 km) and were provided by Data Center for Resources and Environmental Sciences, Chinese Academy of Sciences (RESDC) (http://www.resdc.cn, accessed on 5 November 2020). Land use classification includes six first-level categories, namely, arable land, woodland, rangeland, waterarea and -conservancy facility land, construction land, and unused land and 25 s-level categories. According to the second-level classification standard of the land-use/-cover classification system for remote-sensing monitoring in China, on the basis of the differentiation of land use functions and types, and the linkage table (Table 1), PLES structure and land use types were established.

**Table 1.** Corresponding table of type between production–living–ecological space (PLES) and land use.

